The FRITZ!Box user interface cannot be opened. After entering entering fritz.box in the address field of the web browser, the error message "Internal communication error (login -1)" is displayed.

Simply proceed as described below. After each measure, check whether the issue persists.

1 Restarting the FRITZ!Box

Unplug your FRITZ!Box by removing the power cable from the electrical outlet.

Plug it in again after 5 seconds.

Note:The FRITZ!Box settings will not be deleted when it restarts. The restart will take about 2 minutes. During this time, you cannot access the FRITZ!Box user interface.

2 Disabling "FritzCall-Plugin"

The following step is only necessary if you are using "FritzCall-Pugin":"FritzCall-Pugin" is not an application from AVM, it is from a different manufacturer. "FritzCall-Pugin" displays calls to the FRITZ!Box on a screen connected to a Dreambox, a SAT receiver, or a similar device.According to our current knowledge, the available version of the plug-in is incompatible with the FRITZ!Box.

Note:The relevant manufacturer can provide you with specific information.